The influence of 3 different navel dips on calf health, growth performance, and umbilical infection assessed by clinical and ultrasonographic examination.

The objectives were to investigate the effect of 3 navel dips on (1) umbilical infection, (2) health events (pneumonia, diarrhea, and arthritis), and (3) average daily gain (ADG) in newborn dairy calves. A secondary aim was to compare the agreement of standardized ultrasonographic examination with clinical examination for the diagnosis of umbilical infection. In a randomized block design, newborn calves were assigned by birth order to 3 treatment groups: Navel Guard (NG; SCG-Solutions Inc., McDonough, GA), 7% iodine tincture (SI), and 2% chlorhexidine gluconate (CH). Treatment consisted of a single dip administration of the umbilicus immediately after removal of the newborn from the calving pen with 1 of the 3 navel dips. Weekly clinical examinations were carried out during the first 4wk of life with special attention being paid to the umbilicus, joints, respiratory tract, and fecal consistency, and included ultrasonographic evaluation of the umbilical structures. Body weight was assessed by using a girth tape at first and last evaluation. Multivariable logistic regression demonstrated no statistical differences in umbilical infection or health events. Multivariable linear regression analysis showed statistical differences in ADG (least squares means ± standard errors) between groups, with 494±29, 571±29, and 516±29g/d in groups NG, SI, and CH, respectively. Overall mortality during the study period was 9.5% (n=40). Postmortem examination identified diarrhea (80%) as the main disorder with 19, 4, and 9 calves in groups NG, SI, and CH, respectively. Kappa values yielded fair [0.30 (95% CI: -0.03-0.63)], good [0.61 (95% CI 0.46-0.75)], moderate [0.53 (95% CI 0.31-0.74)], and moderate [0.49 (95% CI 0.19-0.79)] agreement for detection of omphalitis between clinical and ultrasonographic evaluation in wk 1, 2, 3, and 4, respectively. Agreement was very good for detection of omphaloplebitis, with kappa values (95% CI) of 0.91 (0.80-1.00), 0.87 (0.75-0.98), and 0.90 (0.76-1.00) in wk 2, 3, and 4, respectively, when omphalophlebitis was diagnosed. We detected no difference in the effectiveness of the 3 treatments in the prevention of umbilical infection, pneumonia, diarrhea, or arthritis.

The effect of intrauterine infusion of dextrose on clinical endometritis cure rate and reproductive performance of dairy cows.

The main objective of this study was to evaluate the intrauterine administration use of 200 mL of 50% dextrose solution as a treatment against clinical endometritis (CE); CE cure rate and reproductive performance were evaluated. Additionally, the association of several relevant risk factors, such as retained placenta (RP), metritis, CE, anovulation, hyperketonemia, and body condition score with reproductive performance, early embryonic mortality, and CE were evaluated. A total of 1,313 Holstein cows housed on 4 commercial dairy farms were enrolled in the study. At 7±3 DIM cows were examined for metritis and had blood collected to determine serum ß-hydroxybutyrate concentration. To determine if cows had ovulated at least once before 44±3 DIM, the presence of a corpus luteum was evaluated by ovarian ultrasonography at 30±3 DIM and at 44±3 DIM. At 30±3 DIM, CE was diagnosed using the Metricheck device (SimcroTech, Hamilton, New Zealand); cows with purulent or mucopurulent vaginal discharge were diagnosed as having CE. Cows diagnosed with CE (n=175) were randomly allocated into 2 treatment groups: treatment (intrauterine infusion of 200 mL of 50% dextrose) or control (no infusion). Clinical endometritis cows were re-evaluated as described above at 44±3 DIM, and cows that were free of purulent or mucopurulent vaginal discharge were considered cured. Intrauterine infusion of dextrose tended to have a detrimental effect on CE cure rate, and treatment did not have an effect on first-service conception rate and early embryonic mortality. A multivariable Cox's proportional hazard model was performed to evaluate the effect of several variables on reproductive performance; the variables RP, CE, parity, anovulation, and the interaction term between parity and anovulation were associated with hazard of pregnancy. Cows that did not have RP or CE were more likely to conceive than cows that were diagnosed with RP or CE. Cows that had RP were at 3.36 times higher odds of losing their pregnancy than cows that did not have RP. In addition, cows diagnosed with CE were at 2.16 higher odds of losing their pregnancy than cows without CE. In conclusion, intrauterine infusion of 200 mL of 50% dextrose solution as a treatment for CE had a strong statistical tendency to decrease CE cure rate, did not improve first-service conception rate and early embryonic mortality, and did not decrease calving-to-conception interval.

An economic analysis of hyperketonemia testing and propylene glycol treatment strategies in early lactation dairy cattle.

The purpose was to develop stochastic economic models which address variation in disease risks and costs in order to evaluate different simulated on-farm testing and propylene glycol (PG) treatment strategies based on herd hyperketonemia (HYK) incidence during the first 30 DIM. Data used in model development concerning the difference in health and production consequences between HYK and non-ketotic cows were based on results from 10 studies representing over 13,000 cows from 833 dairy farms in North America, Canada, and Europe. Inputs for PG associated variables were based on a large field trial using cows from 4 free-stall dairy herds (2 in New York and 2 in Wisconsin). Four simulated on-farm testing and treatment strategies were analyzed at herd HYK incidences ranging from 5% to 80% and included: 1) treating all cows with 5d of PG starting at 5 DIM, 2) testing all cows for HYK 1 day per week (e.g. Mondays) from 3 to 16 DIM and treating all positive cows with 5d of oral PG, 3) testing all cows for HYK 2 days per week (e.g. Mondays and Thursdays) from 3 to 9 DIM and treating all positive cows with 5d of oral PG, and 4) testing all cows for HYK 3 days per week (e.g. Mondays, Wednesdays, and Fridays) from 3 to 16 DIM and treating all positive cows with 5d of oral PG. Cost-benefit analysis included the costs associated with labor to test cows, ß-hydroxybutyrate test strips, labor to treat cows, PG, and the associated gain in milk production, decrease in DA and early removal risks of PG treated HYK positive cows compared to non-treated HYK positive cows. Stochastic models were developed to account for variability in the distribution of input variables. Per 100 fresh cows in a herd with an HYK incidence of 40%, the mean economic benefits of the 4 different strategies were $1088, $744, $1166, and $760, respectively. Testing cows 2 days per week from 3 to 9 DIM was the most cost-effective strategy for herds with HYK incidences between 15% and 50%; above 50%, treating all fresh cows with 5d of PG was the most cost-effective strategy. These results show that for herds similar to those used in model, when herd HYK incidences rise above 25%, almost any HYK testing and treatment protocol will be economically beneficial for the farm.

Reproductive performance of dairy cows resynchronized after pregnancy diagnosis at 31 (±3 days) after artificial insemination (AI) compared with resynchronization at 31 (±3 days) after AI with pregnancy diagnosis at 38 (±3 days) after AI.

An important part of reproductive management programs on dairy farms is identification of nonpregnant cows and early re-insemination to achieve higher pregnancy rates. The objective of this study was to compare the effect on reproductive performance and pregnancy loss of 2 pregnancy diagnosis protocols: (1) pregnancy diagnosis performed 31±3 d after artificial insemination (AI) by ultrasonography (ULTRA), and (2) resynchronization started 31±3 d after AI but with pregnancy diagnosis performed 38±3 d after AI by palpation per rectum (PALP). Cows were randomly allocated into 1 of the 2 management programs. For cows enrolled in ULTRA, the initial pregnancy diagnosis (P1) was performed by transrectal ultrasonography at 31±3 d after AI, and nonpregnant cows were enrolled in the Ovsynch protocol for resynchronization of ovulation to receive timed AI (TAI). For cows enrolled in PALP, the Ovsynch protocol for resynchronization of ovulation to receive TAI was initiated at 31±3 d after AI regardless of pregnancy status, with the initial pregnancy diagnosis (P1) performed by palpation per rectum at 38±3 d after AI. For both groups, reconfirmation of pregnancy was performed by palpation per rectum at 63±3 d after AI (P2). Cows were inseminated after detection of estrus by use of activity monitors at any time during the study. Two levels of activity were used as a reference for cows AI after detection of estrus based on activity: an activity level of ≥2 when a cow was coded in DairyComp 305 (Valley Agricultural Software, Tulare, CA) as open (nonpregnant) and an activity level of ≥3 when the pregnancy status of the cow was unknown. Our findings showed that the odds of pregnancy loss cows in ULTRA was 2 times higher between P1 and P2 compared with that of cows in PALP. Furthermore, pregnancy diagnosis method (ULTRA vs. PALP) did not have a significant effect on the Cox proportional hazard of pregnancy at P2. The occurrence of assisted parturition, metritis, or retained placenta was associated with a reduced hazard of pregnancy at P2. An economic analysis was performed by simulating a 1,000-cow commercial dairy herd using a decision support tool to estimate the net present value (NPV; $/cow per yr) from using the 2 different pregnancy diagnosis methods. The analysis revealed minor differences in NPV between the programs, depending on the cost to perform ULTRA or PALP. In summary, we observed no difference in the reproductive performance and only a minor and fluctuating economic difference when using either PALP or ULTRA for pregnancy diagnosis of dairy cows.

Evaluation of cytokine expression by blood monocytes of lactating Holstein cows with or without postpartum uterine disease.

Whereas neutrophils are the main phagocytic leukocytes, monocytes and macrophages are actively involved in immunomodulation after infection. Recent studies have demonstrated that neutrophil function is impaired by the state of negative energy balance around parturition, and that cows that develop uterine disease have a greater degree of negative energy balance than healthy cows. The objectives of this study were to compare monocyte gene expression and protein secretion of selected cytokines from calving to 42 d after calving in Holstein cows that did or did not develop uterine disease. Real time quantitative RT-PCR (Tumor necrosis factor-α (TNFα), Interleukin (IL)-1ß, IL-6, IL-8 and IL-10) and ELISA (TNFα, IL-1ß and IL-8) were used to evaluate cytokine response following in vitro stimulation of blood-derived monocytes with irradiated E. coli. Relative to unstimulated cells, E. coli-stimulated monocytes from cows with metritis had lower gene expression of key pro-inflammatory cytokines than healthy cows from calving to 14 d after calving (TNFα at 0, 7, and 14 d after calving, IL-1ß and IL-6 at 7 and 14 d after calving; P < 0.05). There were no significant differences between groups for expression of IL-8 or the anti-inflammatory cytokine IL-10. This was due, in part, to higher gene expression in unstimulated monocytes (TNFα, IL-1ß, IL-6 and IL-10) in early lactation from cows with metritis. Expression of mRNA in stimulated cells (relative to housekeeping genes) was lower for TNFα (7 and 14 d postpartum) and for IL-10 (7 and 14 d postpartum) in cows with metritis. Concentration of TNFα was lower in the culture medium of E. coli-stimulated monocytes from cows with metritis than healthy cows at calving and 7 and 21 d after calving (P < 0.05). Circulating cytokine concentrations were not different between groups for IL-8 and were below the limits of detection for TNFα and IL-1ß. Cytokine gene expression and production were similar between healthy cows and cows that developed endometritis, diagnosed cytologically at 42 d after calving. We concluded that altered levels of expression and production of pro-inflammatory cytokines postpartum could contribute to impaired inflammatory response and predispose cows to development of metritis.

Association between uterine disease and indicators of neutrophil and systemic energy status in lactating Holstein cows.

The objective of this study was to evaluate the association between uterine disease and indicators of neutrophil (PMN) and systemic energy status in dairy cows. Peripheral blood (120 mL) was collected weekly from 84 Holstein cows for PMN isolation and plasma collection from calving until 42 d in milk (DIM). The final analysis included 80 cows. Of those, 20 cows were classified as having metritis (fetid uterine discharge and fever), 15 as having subclinical endometritis (SCE; >or=10% PMN on uterine cytology), and 45 as healthy controls. Plasma haptoglobin concentration was increased only in cows that developed metritis. Neutrophil glycogen content was reduced in cows developing metritis compared with healthy cows on the day of calving and at 7 and 42 DIM. Cows with SCE had lower PMN glycogen content than healthy cows at 7, 28, and 42 DIM. Blood glucose was affected by disease status within parity. Primiparous metritis cows had greater blood glucose concentrations than healthy primiparous cows. Multiparous metritis cows tended to have lower blood glucose concentration than multiparous SCE cows. Cows that developed metritis and SCE had or tended to have greater NEFA and BHBA than healthy cows, mainly around calving. At calving, cows that developed metritis had higher plasma estradiol concentration than healthy cows and greater plasma cortisol than cows that had SCE. Plasma insulin was not affected. Plasma glucagon was increased for SCE cows. Cows that developed uterine disease experienced a greater degree of negative energy balance and had decreased lower intracellular PMN glycogen levels, which could be a major predisposing factor for disease because of decreased availability of oxidative fuels.

Ovsynch versus Ultrasynch: reproductive efficacy of a dairy cattle synchronization protocol incorporating corpus luteum function.

The objective was to compare the reproductive efficacy of Ultrasynch, a synchronization program based on functionality of the corpus luteum as determined by ultrasonography, with an Ovsynch protocol. A randomized field trial was conducted on a commercial dairy in Cayuga County, New York, during scheduled weekly pregnancy examinations. Cows (n=745) determined nonpregnant 28 to 34 d after artificial insemination (AI) were randomly assigned to Ultrasynch or Ovsynch protocols. Cows assigned to the Ultrasynch management program (n=366) were treated based on corpus luteum (CL) diameter: cows with a CL > 23 mm received an injection of PGF(2alpha) and were bred via AI following detection of estrus (Ultra-PGF), whereas cows with a CL < or = 23 mm received injections and were bred on an Ovsynch protocol. Cows assigned to the Ovsynch management program (n=379) were placed on an Ovsynch protocol regardless of CL diameter. Pregnancy status was rechecked 28 to 34 d after AI; cows determined nonpregnant after initial enrollment were maintained in their assigned management group and received treatments based on CL diameter if in the Ultrasynch group and Ovsynch treatments if in the Ovsynch group. Hazard of pregnancy was similar between Ultrasynch and Ovsynch (hazard ratio=1.10, 95% confidence interval=0.88-1.36). Median days to conception were 98 and 87 for Ultrasynch and Ovsynch, respectively. The detection of estrus rate of cows in the Ultra-PGF group was 49%; better performance of an Ultrasynch management program may be achievable in a herd with a higher rate of estrus detection.

Effect of early postpartum ovulation on fertility in dairy cows.

Our objectives were to determine the effects of early ovulation on fertility and uterine health of dairy cows. Four hundred and forty-five Holstein cows (185 primiparous and 260 multiparous) from five herds were used. Blood samples were collected at 21, 35 and 49 days in milk (DIM) and cows were considered to be cyclic at 21 DIM (Cyc21) if serum progesterone (P4) concentration was above 1 ng/ml, cyclic by 49 DIM (Cyc49) if P4 concentration was above 1 ng/ml at 35 or 49 DIM, or not cyclic (NotCyc) if P4 concentration was below 1 ng/ml at all sample times. Endometrial cytology for diagnosis of subclinical endometritis was examined at 49 DIM in a subset of 414 cows. Cows in the group Cyc21 had increased hazard of insemination, for the first service, compared with cows in Cyc49 [hazard ratio (HR) = 1.40; 95% CI = 1.10-1.79; p = 0.006] and NotCyc (HR = 2.07; 95% CI = 1.52-2.82; p < 0.001). Cows in the Cyc49 group also had increased hazard of insemination compared with cows in the NotCyc group (HR = 1.47; 95% CI = 1.13-1.93; p = 0.005). Median days to insemination were, respectively, 71, 76 and 96 for cows in Cyc21, Cyc49 and NotCyc groups. Cows in Cyc21 had greater first service pregnancy per AI than Cyc49 [38.6 vs 28.1%; adjusted odds ratio (AOR) = 1.67; 95% CI = 1.01-2.75; p = 0.04] and NotCyc (38.6 vs 23.6%; AOR = 2.08; 95% CI = 1.08-4.00; p = 0.03). Pregnancy per AI was similar in Cyc49 and NotCyc cows (28.1 vs 23.6%; AOR = 1.25; 95% CI = 0.70-2.24; p = 0.45). Cows in Cyc21 had increased hazard of pregnancy up to 300 DIM compared with Cyc49 (HR = 1.52; 95% CI = 1.17-1.96; p = 0.002) and NotCyc (HR = 1.98; 95% CI = 1.41-2.78; p < 0.001). Cows in Cyc49 tended to have increased hazard of pregnancy compared with NotCyc (HR = 1.31; 95% CI = 0.96-1.77; p = 0.09). Median days to pregnancy were, respectively, 103, 147 and 173 for cows in Cyc21, Cyc49 and NotCyc groups. Cows in the Cyc21 group had decreased prevalence of subclinical endometritis compared with cows in the NotCyc group (29.9 vs 43.7%; AOR = 0.53; 95% CI = 0.29-0.97; p = 0.04); however, the prevalence did not differ from the Cyc49 group (29.9 vs 39.1%; AOR = 0.68; 95% CI = 0.41-1.14; p = 0.15). Cyc49 cows had similar prevalence of subclinical endometritis compared with NotCyc cows (AOR = 0.77; 95% CI = 0.46-1.29; p = 0.32). Early postpartum ovulation was associated with improved uterine health and fertility.

Effect of prostaglandin F2alpha on subclinical endometritis and fertility in dairy cows.

The objectives were to determine the effects of PGF(2alpha) treatment on the prevalence of subclinical endometritis (SCE) and fertility of dairy cows. A total of 406 Holstein cows (167 primiparous and 239 multiparous) from 5 herds were used. Uterine lavage for diagnosis of SCE, PGF(2alpha) treatment, evaluation of body condition scores (BCS), and collection of blood samples for estrous cyclicity determination were performed at 21, 35, and 49 d in milk (DIM). Polymorphonuclear cells (PMN) were quantified and thresholds for diagnosing SCE were selected by receiver operating characteristics analysis. Cows classified as having SCE at 35 DIM (>or=6.5% PMN) and 49 DIM (>or=4.0% PMN) had increased time to pregnancy; however, cows classified as having SCE at 21 DIM (>or=8.5% PMN) did not. Median days to pregnancy were delayed by 30 (151 vs. 121 d) and 40 (169 vs. 129) d for cows classified as having SCE at 35 and 49 DIM, respectively. Treatment with PGF(2alpha) did not affect the prevalence of SCE either at 35 (37.9 vs. 38.4%) or at 49 DIM (34.0 vs. 40.4%). Treatment with PGF(2alpha) did not affect time to first insemination (AI; median 76 DIM for cows treated with PGF(2alpha); 79 DIM for control. Nonetheless, PGF(2alpha) treatment increased pregnancy to first AI in all the cows (35.5 vs. 24.1%) and hazard ratio (HR) of pregnancy in cows with BCS

The association between foot lesions and culling risk in Ontario Holstein cows.

The objective was to determine the association between specific foot lesions and culling in dairy cows. Using 5 trained professional hoof trimmers, data from 6,513 cows in 157 herds were recorded for analysis. During the study period, 1,293 cows (19.9%) were culled. Infectious lesions were most frequent in nonculled cows, whereas hoof horn lesions were most common in the culled cows. Median time to culling was 188 d [95% confidence interval (CI): 175-198 d] for cows without a lesion and 157 d (CI: 149-168 d) for cows with a lesion. Time from hoof trimming to culling was used to model the association between foot lesions and culling hazard. The final multivariate Cox proportional hazards model included heifers, infectious lesions, white line lesions, hemorrhages, sole ulcers, other lesions, and free-stall housing as covariates. Results of the final model showed that infectious hoof lesions had no significant association with culling. Yet, the hazard ratios for white line lesions, ulcers, and hemorrhage were 1.72 (CI: 1.39-2.11), 1.26 (CI: 1.05-1.52), and 1.36 (CI: 1.16-1.59), respectively. The association with culling for the grouped variable "other lesions" was time dependent and decreased with time. These results illustrate that there were significant associations with cow productivity for hoof horn lesions found at routine hoof trimming and that emphasis should be placed on proper treatment and earlier detection of these foot lesions.

Herd-level risk factors for seven different foot lesions in Ontario Holstein cattle housed in tie stalls or free stalls.

Worldwide, there is considerable between-herd variation within individual foot lesion prevalence studies. This variation suggests that herd-level risk factors are important from a prevention perspective. The objective was to determine the effect of selected risk factors on the prevalence of 7 foot lesions in both tie-stall and free-stall housing systems. As part of a cross-sectional foot lesion study 5 hoof trimmers recorded lesions for all cows that were foot trimmed in a herd. In addition, they completed a risk factor questionnaire for each herd. The impact of specific risk factors was evaluated using separate multi-variable models for both free-stall and tie-stall herds. The lesions evaluated were digital dermatitis, sole ulcer, sole hemorrhage, heel horn erosion, white line separations, white line abscess, and interdigital fibroma. Model types were selected based on herd-level lesion distribution. Detrimental risk factors identified in free-stall housing included increased alley scraping frequency (2.2- to 2.4-fold for sole ulcers) and trimming in summer or fall (-0.2-fold vs. spring and winter for digital dermatitis). Protective risk factors in free stalls included intermediate bedding depth (0.4-fold for 2.5 to 7.5 cm vs. more or less bedding for interdigital fibroma) and trimming heifers before calving (0.1-fold for white line abscess). In tie-stall herds no protective risk factors were identified. Detrimental risk factors for lesions in tie stalls included year-round access to outside areas (2.1-fold increase in digital dermatitis, 3.5-fold for white line separation, and 7.0-fold for interdigital fibroma vs. no or only seasonal exercise access), routine spraying of feet (2.0-fold increase in digital dermatitis), larger herds (3.0-fold increase in interdigital fibroma vs. <41 cow herds), and the use of wood bedding material (6.5-fold vs. straw bedding for interdigital fibroma). The risk factors identified need further evaluation to determine the temporal relationships, as well as whether the relationships with foot lesions are causal.

Herd- and cow-level prevalence of foot lesions in Ontario dairy cattle.

The objectives of this cross-sectional study were to determine herd-level and cow-level prevalence estimates for 11 foot lesions in Ontario dairy cattle. Foot lesions were recorded by 5 hoof trimmers on 13,530 cows in 204 Ontario dairy herds from March 2004 to May 2005. Significant differences existed between free-stall and tie-stall housing. In free-stall housing systems, 46.4% of cows had a foot lesion, compared with 25.7% of cows in tie-stall barns. Digital dermatitis was the most common lesion in tie stalls, occurring in 9.3% of cows and 69.7% of the herds, whereas in free-stall herds, 22.7% of cows and 96.7% of the herds were affected. The most common hoof horn lesions were hemorrhages and ulcers, at 7.7 and 4.7% in tie-stall housing and 11.0 and 9.2% in free-stall housing, respectively. Foot blocks were used to treat 2.2% of cows in free stalls and 0.3% in tie stalls. Intraclass correlation coefficients ranged from 9.5 to 17.3 for hoof horn lesions and 28.0 to 38.7 for infectious lesions. In summary, foot lesions diagnosed at the time of hoof trimming are common in Ontario, and appropriate treatment for hoof horn lesions is low.

Strategies to analyze milk losses caused by diseases with potential incidence throughout the lactation: a lameness example.

The objective of this study was to test the hypothesis that lameness incidence in lactating dairy cows decreases milk production compared with controls and to determine the best method of the 5 combinations of 2 study designs (retrospective cohort and retrospective matched cohort) and 3 repeated measures statistical methods: ANOVA (with binary classification of lameness); ANOVA with a lameness index (LAMIX) as the variable of interest; and analysis of covariance (ANCOVA, controlling for mean milk production for the first 3 wk of lactation and with a binary classification of lameness). Data were from 1 dairy farm located near Ithaca, NY, and from cows that calved between January 1, 2004 and January 1, 2007. The LAMIX was defined as -1, -2, -3, -4, and -5 = 1, 2, 3, 4, and > or =5 mo before lameness was detected, respectively; 1, 2, 3, 4, and 5 = 1, 2, 3, 4, and 5 mo after diagnosis, respectively; and 0 = cows that were never lame. With the binary lameness classification analyzed by repeated measures ANOVA, there was no effect of lameness on milk yield. The model was biased because lame cows had higher milk yields before lameness compared with nonlame cows. When the LAMIX was used, milk production before lameness was greater than after lameness (3.1 +/- 0.28 kg/d). Yet, point estimates generated for LAMIX were inaccurate because of the multicollinearity detected between LAMIX and week of lactation and because of the inability of adjusting the least squares means for the interaction of LAMIX and week of lactation. Therefore, the most appropriate models were the ANCOVA models (both for the matched and nonmatched retrospective-cohort designs). The estimated losses associated with lameness were 314 and 424 kg/cow per 305-d lactation, respectively, for the matched and nonmatched designs. Furthermore, high milk yield in the beginning of the lactation was a risk factor for lameness.

Optimizing the accuracy of detecting a functional corpus luteum in dairy cows.

The objectives were to evaluate the accuracy of detecting a functional CL by transrectal palpation and ultrasonography, and to optimize the accuracy of detecting a functional CL by ultrasonography in Holstein cows. In Experiment 1, four veterinarians performed transrectal palpation in 1250 cows at 37 d in milk (DIM), two veterinarians repeated transrectal palpation in 823 cows at 58 DIM, and one veterinarian performed 206 ultrasonographic examinations at 37 DIM. In Experiment 2, 987 and 983 ultrasonographic examinations were performed at 21 and 24 d after AI by one veterinarian for detection and measurement of CL. Cows with a blood progesterone concentration > or =1ng/mL were assumed to have a functional CL. Sensitivity and specificity were optimized using receiver operating characteristic analysis. In Experiment 1, sensitivity of transrectal palpation for diagnosing a functional CL ranged from 33.3 to 59.9% at 37 DIM and from 48.3 to 68.4% at 58 DIM, whereas specificity ranged from 76.7 to 93.2% at 37 DIM and from 73.3 to 86.7% at 58 DIM. Sensitivity and specificity for ultrasonography were 89.4 and 45.7%, respectively. In Experiment 2, the sensitivity and specificity of ultrasonography were 97.3 and 38.1% at 21 d after AI, and were 97.9 and 51.0% at 24 d after AI. Sensitivity and specificity were optimized using a cutoff diameter of 23mm at 21 d and 22mm at 24 d, which resulted in sensitivity and specificity of 87.2 and 83.0% at 21 d, and 89.5 and 89.4% at 24 d after AI, respectively. Sensitivity was low and specificity was high for transrectal palpation, whereas ultrasonography resulted in high sensitivity and low specificity. Using a cutoff diameter during ultrasonography improved accuracy of detection of a functional CL compared with either ultrasonography without cutoff or transrectal palpation.

Stillbirth parturition reduces milk production in Holstein cows.

Stillbirth is defined as calf mortality shortly before, during, or shortly after parturition. Economic losses to the dairy industry in the U.S. just due to the loss of replacement heifers were estimated to be $125 million per year. Our objective in this study was to evaluate the effect of stillbirth on the dam's subsequent lactation. Data were collected from 20 farms in the U.S.A. (19 from NY, one from IN) from May 2005 until September 2006. Calving-ease scores (scale of 1-5; no problem and extreme difficulty, respectively) and stillbirths were recorded by farm personnel. We used 32,299 calvings for the final analysis where 6.5% of the calvings were stillbirths. The incidence of stillbirths for primiparous cows was 10.7% (of 11,891) and 4% (of 20,408) for multiparous cows. Stillbirth parturition significantly reduced milk production (-1.1 kg/day). The losses in milk production were evaluated in a generalized mixed linear model analysis. The daily milk production for cows with stillbirths was 34.2 kg, compared to 35.3 kg for the cows that had a live calf. Milk-production reduction was greatest early in lactation and declined afterwards. Economic losses from stillbirths include not just the lost calf, the reduced survival, and increased days open but also the decreased milk yield.

Visual locomotion scoring in the first seventy days in milk: impact on pregnancy and survival.

Our hypotheses were that cows classified as lame during the first 70 d in milk have more days from calving to conception and a greater hazard of dying or being culled compared with cows that were not classified as lame. Our objective was to estimate the detrimental effects of lameness on calving-to-conception interval and hazard of dying or being culled in lactating Holstein cows. Data were collected from 5 dairy farms located in upstate New York from November 2004 to June 2006. The design was a prospective observational cohort study. Cows were assigned a visual locomotion score (VLS) using a 5-point scale: 1 = normal, 2 = presence of a slightly asymmetric gait, 3 = the cow clearly favored 1 or more limbs (moderately lame), 4 = severely lame, to 5 = extremely lame (nonweight-bearing lame). In total 1,799 cows were enrolled. In 2 alternative categorizations, cows were considered lame if at least 1 VLS was > or =3 during the first 70 d in milk, and if at least 1 VLS was > or =4 for the same period they were considered lame. Lameness (VLS > or =3) was detected at least once in 26.5, 54.2, 33.9, 51.8, and 39.3% of all cows in farms 1 to 5, respectively. The hazard ratio of being detected pregnant was 0.85 for lame cows (VLS > or =3) vs. nonlame cows; hence, lame cows were at a 15% lower risk of pregnancy than nonlame cows. When lameness was redefined as VLS > or =4, the hazard ratio of been detected pregnant was 0.76 for lame cows vs. cows with VLS <4. Lameness increased the hazard ratio of culling/death, 1.45 and 1.74 for VLS > or =3 and VLS > or =4, respectively, vs. cows with VLS <3 and VLS <4, respectively. In summary, lameness significantly decreased the hazard of pregnancy and increased the hazard of culling/death. The detrimental effects were amplified when considering only severely lame and non-weight-bearing cows.

Association between a visual and an automated locomotion score in lactating Holstein cows.

Two studies were conducted to evaluate visual locomotion scoring (VLS) and Stepmetrix locomotion scoring (SLS) in detecting painful digit lesions. In study 1, one veterinarian performed VLS. Cows with VLS > or = 3 were hoof trimmed and the presence or absence of a painful lesion (PL), defined as a reaction to digital pressure, was recorded. A strongly increasing pattern in the proportion of cows with PL was detected as VLS increased. The proportions of cows with painful lesions were 5.6% (n = 53), 20.1% (n = 78), 55.5% (n = 164), 79.9% (n = 159), and 100% (n = 5) for VLS 1 to 5, respectively. Study 2 was conducted on a different farm. The entire farm was visually locomotion scored by 3 veterinarians on the same day, and the cows were Stepmetrix locomotion scored by walking through the Stepmetrix system. Every cow was trimmed during the following 2 d by 1 of 8 professional hoof trimmers. The 3 veterinarians identified, scored, and recorded any PL. Interobserver agreement for the 3 veterinarians had a kappa coefficient of between 0.45 and 0.48 +/- 0.05. In total, 518 cows were used in the analysis, from which 11.2% were identified with a PL. Of the cows diagnosed with a PL, 32.8% were detected with a sole ulcer, 25.9% with white line disease, 13.8% with white line abscess, and 27.5% with other diseases. A receiver operating characteristic analysis was performed; the area under the curve was larger for VLS (0.80; 95% confidence interval, 0.76 to 0.83) than SLS (0.62; 95% confidence interval, 0.57 to 0.66). When performed by trained veterinarians, VLS performed better than SLS in detecting PL.

Effect of stillbirths on dam survival and reproduction performance in Holstein dairy cows.

The objectives of this study were to evaluate the effect of stillbirth on survival and reproductive performance of lactating dairy cows. Data were collected from 2 different regions of the US calving-ease scores (CES) were recorded by farm personnel on a scale of 1 (no problem) to 5 (extreme difficulty). Stillbirths were recorded by farm personnel. The final analysis included 13,608 calvings of which 93.4% were live calves and 6.6% stillbirths. An increasing or decreasing trend in the incidence of stillbirth by parity and by CES was analyzed by Cochran-Armitage trend tests. A significant decreasing trend in the incidence of stillbirth by parity group was detected. The incidence of stillbirth increased as the CES increased. The incidence of stillbirths was 3.6, 11.2, 25.9, and 60.1% for CES score 1, 2, 3, and 4, respectively. Dam survival in the herd and reproductive performance were analyzed by the Cox proportional hazards model. Variables that decreased dam survival time were stillbirths, primiparity, and CES of 3 and 4. The variables that reduced reproductive performance were stillbirths, multiparity, male calves, and CES of 3 and 4. Cows that had stillbirths had significantly increased risk of culling/death throughout the lactation and increased median days open by 88 d compared with cows that had live calves. In conclusion, losses from stillbirths are far greater than just the value of the calf.

Field technique for the resection of the distal interphalangeal joint and proximal resection of the deep digital flexor tendon in cows.

A modified technique for the resection of the distal interphalangeal joint and the proximal resection of the deep digital flexor tendon in cows is described. Septic arthritis of the joint was diagnosed in eight Holstein cows and treated in the field. Four of the cows were diagnosed with ascending tendonitis during the resection of the joint and their tendons were also resected. All the animals remained moderately to severely lame for two weeks postoperatively but quickly recovered and were sound within five months. Eight months after the last surgery only one cow had been culled, 321 days after its surgery, for reproductive failure. The other seven cows had survived for a mean period of 308 days, with a range from 235 to 392 days.

Evaluation of progesterone supplementation in a prostaglandin F2alpha-based presynchronization protocol before timed insemination.

The objective of the study was to determine the effects of treatment with a controlled internal drug-release (CIDR) insert containing progesterone in a PGF2alpha-based presynchronization protocol on pregnancy rates at first service in lactating Holstein cows. A total of 1,318 (656 treatment and 662 control) cows from 5 farms were used in the analysis. Cows received a CIDR insert as part of the presynchronization protocol of 2 PGF2alpha injections given 14 d apart. The CIDR insert was applied during 7 d before the second PGF2alpha injection, whereas control cows received no CIDR insert. Serum progesterone concentrations were measured in samples collected at 37 +/- 3 d in milk (DIM; 7 d after the first PGF2alpha injection) and at 58 +/- 3 DIM, just before initiation of the Ovsynch protocol. According to serum concentrations of progesterone, cows were classified as having either high (> or = 1 ng/mL) or low (< 1 ng/mL) progesterone. The proportion of cows with low progesterone at 37 +/- 3 DIM was similar for cows treated later with the CIDR insert (60.7%; n = 654) and for control cows (59.2%; n = 657). In contrast, use of the CIDR insert resulted in fewer low-progesterone cows (17.4%; n = 402) compared with control cows (30.6%; n = 399) at 58 +/- 3 DIM. No significant effect of the CIDR insert was detected on overall pregnancy rates. Pregnancy rates, as measured by the percentage of cows pregnant at 37 +/- 3 d post timed artificial insemination, for control cows having high or low progesterone at 58 +/- 3 DIM were 46.6 and 22.1%, respectively. For the CIDR group, pregnancy rates were 40.4 and 11.4%, respectively, for high- and low-progesterone cows at 58 +/- 3 DIM. Overall pregnancy rates were 36.4 and 34.5% for control cows and cows receiving the CIDR insert, respectively. A significant decreasing trend was observed in the proportion of cows having low progesterone as the body condition score increased, at 37 +/- 3 and 58 +/- 3 DIM. A significant increasing trend in the pregnancy rate was observed as body condition score increased. In conclusion, incorporation of CIDR inserts into a presynchronization protocol reduced the proportion of cows having low progesterone; however, the pregnancy rate did not differ between control cows and those receiving the CIDR insert. Earlier expression of estrus after the second PGF2alpha injection, and consequently improper timing of initiation of the Ovsynch protocol, could have negatively affected fertility in the CIDR-treated cows.